1. Field of the Invention
The present invention relates to a device for zooming images, and more particularly, to a device for zooming images by using a single clock and a method thereof.
2. Description of the Related Art
The image zooming device is commonly used to convert a source image into a destination image with a different size, in which the size of the image is generally defined as the length of the image multiplied by the width of the image, and a pixel is commonly used as an unit of the length and width of the image. The source image is either a graphic image generated by the computer or a video frame generated by the television. In addition, the source image is generally composed of one or more continuous frames, and each frame contains multiple scanning line data.
FIG. 1 schematically illustrates a flow chart of a conventional method for zooming images that had been disclosed in U.S. Pat. No. 5,739,867. Referring to FIG. 1, first in step S110, pixel data of scan lines of a source image are received by using a source clock signal (SCLK). In step S120, a destination clock signal (DCLK) is calculated. The destination clock signal (DCLK) is used for generating a magnified image in a frame rate which is the same as the one used in receiving the source image. In step S130, the source image is magnified in both horizontal and vertical directions. A commonly used magnifying technique comprises the steps of copying the pixel data, and using the coped extra pixel data and the pixel data of the source image to generate the magnified image. In step S140, a magnified pixel data is provided by using the object clock signal (DCLK), thus the magnified image is generated in the frame rate which is the same as the one used in receiving the source image. Finally, in step S150, if it is required to be displayed on the display, an interpolation operation is performed on the magnified image pixel data in order to generate the destination image.
The conventional technique mentioned above applies a so-called multi-clock domain technique to zoom in and out the images and requires different operating circuits and methods to magnify and shrink the image. Accordingly, the complexity of the circuit is increased.